Final answer:
Lack of motivation is not a reason to terminate an exercise test; legitimate reasons include physical exhaustion, injury or illness, and completion of the test. So, the correct answer is option 1.
Step-by-step explanation:
A reason to terminate an exercise test would not include lack of motivation. Legitimate reasons to stop an exercise test include physical exhaustion, injury or illness, and completion of the test. While someone may feel less motivated to continue an exercise test, it is not a medical or safety reason to terminate it.
In comparison, physical exhaustion, injury or illness pose immediate risks to the individual's health and should prompt termination of the test. Similarly, when the test is completed as per the predefined endpoint, it is standard to stop the test.
So, the correct answer is option 1.